Search Publications
JWST PEARLS. Prime Extragalactic Areas for Reionization and Lensing Science: Project Overview and First Results
Finkelstein, Steven L.; Hathi, Nimish P.; Holwerda, Benne W. +82 more
We give an overview and describe the rationale, methods, and first results from NIRCam images of the JWST "Prime Extragalactic Areas for Reionization and Lensing Science" (PEARLS) project. PEARLS uses up to eight NIRCam filters to survey several prime extragalactic survey areas: two fields at the North Ecliptic Pole (NEP); seven gravitationally le…
Free-floating Planet Mass Function from MOA-II 9 yr Survey toward the Galactic Bulge
Fukui, Akihiko; Sumi, Takahiro; Bond, Ian A. +25 more
We present the first measurement of the mass function of free-floating planets (FFPs), or very wide orbit planets down to an Earth mass, from the MOA-II microlensing survey in 2006-2014. Six events are likely to be due to planets with Einstein radius crossing times t E < 0.5 days, and the shortest has t E = 0.057 ± 0.016 d…
Hubble Space Telescope Transmission Spectroscopy for the Temperate Sub-Neptune TOI-270 d: A Possible Hydrogen-rich Atmosphere Containing Water Vapor
Madhusudhan, Nikku; Mikal-Evans, Thomas; Crossfield, Ian J. M. +6 more
TOI-270 d is a temperate sub-Neptune discovered by the Transiting Exoplanet Survey Satellite (TESS) around a bright (J = 9.1 mag) M3V host star. With an approximate radius of 2 R ⊕ and equilibrium temperature of 350 K, TOI-270 d is one of the most promising small exoplanets for atmospheric characterization using transit spectroscopy. He…
Terrestrial- and Neptune-mass Free-Floating Planet Candidates from the MOA-II 9 yr Galactic Bulge Survey
Udalski, Andrzej; Mróz, Przemek; Fukui, Akihiko +28 more
We report the discoveries of low-mass free-floating planet (FFP) candidates from the analysis of 2006-2014 MOA-II Galactic bulge survey data. In this data set, we found 6111 microlensing candidates and identified a statistical sample consisting of 3535 high-quality single-lens events with Einstein radius crossing times in the range 0.057 < t
Assessing the C/O Ratio Formation Diagnostic: A Potential Trend with Companion Mass
Macintosh, Bruce; Perrin, Marshall D.; Barman, Travis S. +6 more
The carbon-to-oxygen (C/O) ratio in an exoplanet atmosphere has been suggested as a potential diagnostic of planet formation. Now that a number of exoplanets have measured C/O ratios, it is possible to examine this diagnostic at a population level. Here, we present an analysis of currently measured C/O ratios of directly imaged and transit/eclipse…
TESS Hunt for Young and Maturing Exoplanets (THYME). IX. A 27 Myr Extended Population of Lower Centaurus Crux with a Transiting Two-planet System
Vanderburg, Andrew; Latham, David W.; Quinn, Samuel N. +35 more
We report the discovery and characterization of a nearby (~85 pc), older (27 ± 3 Myr), distributed stellar population near Lower Centaurus Crux (LCC), initially identified by searching for stars comoving with a candidate transiting planet from TESS (HD 109833; TOI 1097). We determine the association membership using Gaia kinematics, color-magnitud…
The Absolute Age of M92
Chaboyer, Brian; Boylan-Kolchin, Michael; Weisz, Daniel +3 more
The absolute age of a simple stellar population is of fundamental interest for a wide range of applications but is difficult to measure in practice, as it requires an understanding of the uncertainties in a variety of stellar evolution processes as well as the uncertainty in the distance, reddening, and composition. As a result, most studies focus…
The Orbital and Physical Properties of Five Southern Be+sdO Binary Systems
Gies, Douglas R.; Wang, Luqian; Peters, Geraldine J. +1 more
Close binary interactions may play a critical role in the formation of the rapidly rotating Be stars. Mass transfer can result in a mass gainer star spun up by the accretion of mass and angular momentum, while the mass donor is stripped of its envelope to form a hot and faint helium star. Far-UV spectroscopy has led to the detection of about 20 su…
Unifying High- and Low-resolution Observations to Constrain the Dayside Atmosphere of KELT-20b/MASCARA-2b
Fu, Guangwei; Brogi, Matteo; Désert, Jean-Michel +10 more
We present high-resolution dayside thermal emission observations of the exoplanet KELT-20b/MASCARA-2b using the MAROON-X spectrograph. Applying the cross-correlation method with both empirical and theoretical masks and a retrieval analysis, we confirm previous detections of Fe I emission lines and we detect Ni I for the first time in the planet (a…
Systematic KMTNet Planetary Anomaly Search. VII. Complete Sample of q < 10-4 Planets from the First 4 yr Survey
Han, Cheongho; Udalski, Andrzej; Lee, Chung-Uk +39 more
We present the analysis of seven microlensing planetary events with planet/host mass ratios q < 10-4: KMT-2017-BLG-1194, KMT-2017-BLG-0428, KMT-2019-BLG-1806, KMT-2017-BLG-1003, KMT-2019-BLG-1367, OGLE-2017-BLG-1806, and KMT-2016-BLG-1105. They were identified by applying the Korea Microlensing Telescope Network (KMTNet) AnomalyFinde…